Field of the Invention
The present invention relates to a vehicle meter indicator device designed to show display data, generated on the basis of the rotation speed of an internal combustion engine, on a meter unit as an image.
Description of Related Art
For example, Japanese Patent No. 5000728 discloses a meter indicator device designed to show, as an image, sensor information from sensors provided on a vehicle. If sensor information is acquired at a longer interval than the frame interval at which an image is to be displayed, the meter indicator device updates the image display position in such a manner that the image moves at the frame interval from a starting point to the image display position calculated on the basis of sensor information acquired at present. The starting point is the image display position calculated on the basis of acquired sensor position.
Incidentally, an image displayed on the meter unit making up the meter indicator device is generated on the basis of the latest sensor information detected by sensors. Therefore, when sensor information is acquired at a shorter interval than the frame interval at which an image is to be displayed, and even if sensor information acquired at each interval changes approximately continuously with respect to time, the image displayed on the meter unit at every frame interval, an updating cycle, undergoes a significant change as an on-screen image between an image displayed previously and an image displayed this time, showing an unsmooth and intermittent transformation. Therefore, an occupant of the vehicle feels a sense of discomfort to the image displayed on the meter unit in some cases.
In particular, if the rotation speed of the vehicle's internal combustion engine declines, a conspicuous difference is observed between the rotation speed as sensor information acquired at every acquisition interval and the rotation speed indicated by the image shown on the meter unit at every frame interval. That is, if the frame interval is longer than the acquisition interval, the frame interval cannot cope with the change in rotation speed, thus resulting in an image motion that produces a sense of discomfort. Further, the engine sound becomes smaller with reduction in rotation speed, thus making the occupant more attentive to the meter unit. As a result, the occupant is more likely to feel a sense of discomfort when the on-screen image of the meter unit changes.
A possible countermeasure for such a problem would be to quicken the updating cycle of an on-screen image shown on the meter unit so as to ensure smooth display of the image. However, quickening the updating cycle of the on-screen image leads to heavier calculation load for the on-screen image, thus resulting in higher cost of the computing device for generating images.